Laser printers may emit high levels of potentially hazardous particles, according to a new study.

Some printers released almost as many ultra-fine particles as a smoldering cigarette, said the study appearing on the Los Angeles Times Website on Wednesday.

The study provides the most extensive look yet at particle emissions of office printers, including Canon, Hewlett-Packard, Ricoh and Toshiba models.

"Particles have been shown beyond any doubt to be a health hazard," said study author Lidia Morawska, a physicist at Queensland University of Technology in Australia.

Inhaling fine particles can cause health problems ranging from respiratory irritation to cardiovascular problems and cancer, depending on the particle composition, Morawska said.

The emissions varied widely among printers. Morawska and her colleagues classified 37 printers as non-emitters, eight as mediumor low emitters, and 17 as high emitters.

The study did not consider variables such as printer age or cartridge type, leading to variations even among printers of the same model.

The scientists noted that they found one HP LaserJet 5 to be a high emitter, while another was a non-emitter.

The researchers, however, did not analyze what the particles consisted of.

Morawska recommends that homes and offices have adequate ventilation to ensure that the printer particles are dispersed.

(Xinhua News Agency August 2, 2007)